I feel a loss of power and fuel efficiency after Timing Belt replacement (1 Viewer)

[Vampo]

Hi Everybody,

I recently replaced my timing belt on my rig (Toyota Landcruiser Cygnus 2005 - Same as Lexus Lx470 2005) at 180,000KM. (Engine 2UZ-FE)

I had the job done at my mechanic. I feel a loss of power and fuel efficiency reduction ever since I replaced the belt. Can this happen? or is it in my head?

What happens if the Cam setting weren't identical when the belt was fixed? Is there any way to check if everything is perfect without removing the engine apart gain?

Other that this issue I haven't seen any problems.

Thanks.

 

[looking4lc]

I have a shudder problem right after the timing belt, water pump replacement.
It's known as "rumble strip" in the tranny. I can't figure out what's the relation between replacing timing belt and tranny shudder!
Is it possible missing wire plug?
I did a complete tranny flush yesterday (13 quarts) and the issue is still exist.
I am scratching my head trying to figure it out. Before the replacement I had zero issue in my lx07.
Plan tonight is to disconnect the battery, to reset Ecu, clean and check the TB hose and Air sensor and check all the wiring.
Some say it's a drive shaft (and I hope it is) better not to deal with the tranny.

 

[aging fleet]

First thing I would check are the timing marks, seems yours may be off by a tooth.

 

[onpoint01]

Set your crankshaft pulley to 0 degrees and remove your left and right cam sprocket plastic covers to make sure the cam sprocket mark lines up with the mark on the head.

 

[2001LC]

I've been told that if T-belt is off by one notch, we'd get a CEL. However I can't confirm as I've not had it happen to me. Perhaps someone that has this happen can confirm or dispel for us.

Have you checked for vacuum leak(s).

 

[Patineto]

Around minute 2;56 the fun start..


Timing is something very EXACT, in some engines can even bend Valves and piston, with tragic consequences..

 

[Julian Stead]

I have a shudder problem right after the timing belt, water pump replacement.
It's known as "rumble strip" in the tranny. I can't figure out what's the relation between replacing timing belt and tranny shudder!
Is it possible missing wire plug?
I did a complete tranny flush yesterday (13 quarts) and the issue is still exist.
I am scratching my head trying to figure it out. Before the replacement I had zero issue in my lx07.
Plan tonight is to disconnect the battery, to reset Ecu, clean and check the TB hose and Air sensor and check all the wiring.
Some say it's a drive shaft (and I hope it is) better not to deal with the tranny.

You have mentioned that this problem has only occurred after a radiator replacement. Have you double checked to make sure the bung's where removed on the ATF cooler pipes on the radiator prior to fitment. Was the radiator OEM, If not I would double check that fluid passes through the ATF cooler.

I just done this job myself, I plugged the transmission lines to the radiator and fluid lose was minimal. Not enough to cause issues. Like I mentioned earlier I would check there are no restrictions in the lines or radiator.

 

[ITRJ]

Check your timing. It can cause poor fuel economy/power loss if incorrect

 

[Vampo]

Thank you everybody for your replies. I'll get the timing belt checked. BTW is there anyway of confirming a timing issue before removing the engine ? e.g. through Techstream.

Thanks.

 

[Julian Stead]

Is that a typo, as you don't need to remove the engine, its just a couple of covers that need removing to check the timing.

 

[Vampo]

Is that a typo, as you don't need to remove the engine, its just a couple of covers that need removing to check the timing.

Sorry, what i meant was, is there a way to check timing without messing around with the engine e.g. through techstream or something. (not removing the engine per se). Thanks.

 

[Julian Stead]

I would imagine the vvti engine has a camshaft sensor that will bring on a light and a fault code. But non vvti I would just use the marks, if you know what your looking at with techstream I am sure you will see some abnormality, but again I still think it would be better to check the marks.

 

[Vampo]

The reason I'm suspecting the timing issue is, I know that the mechanic has having some difficulty perfectly aligning the Crank, CAM1 and CAM2 marks and putting the new timing belt (Mitsuboshi). I believe what he mentioned was that the belt teeth don't perfectly set when all wheels are perfectly aligned. Is this normal ?

 

[Julian Stead]

It should line up, when installing the belt make sure the slack is at the tensioner side otherwise you will be a tooth out. Either install the belt clockwise from the left Cam or anticlockwise from the crank, working the slack to the tensioner. The arrow on the belt points towards the front on the mitsuboshi belt not towards the engine.

Ps there are two crank marks, you want to be set at 0 deg to check.

 

[looking4lc]

You have mentioned that this problem has only occurred after a radiator replacement. Have you double checked to make sure the bung's where removed on the ATF cooler pipes on the radiator prior to fitment. Was the radiator OEM, If not I would double check that fluid passes through the ATF cooler.

I just done this job myself, I plugged the transmission lines to the radiator and fluid lose was minimal. Not enough to cause issues. Like I mentioned earlier I would check there are no restrictions in the lines or radiator.

OEM radiator and job was done along with the Tbelt and water pump.

 

[ITRJ]

The timing marks don't always line up perfectly and can be half a tooth off in some cases but the fact that your mechanic communicated that to you suggest that he wasn't entirely confident in his work. I would suggest going to a different, reputable shop to have the timing checked if your not inclined to check it yourself.

 

[LX470Mack]

Take her down to just under half a tank of gas and empty a bottle of Liqui Molly fuel system cleaner into the tank. It's worth a $20 try. A friends 98 LX has the same issue after a major service and TB change and this made it feel new again.

 

[AMGAndrew]

My right side bank was off half a tooth or so. New timing belt was a little tight to slip on but the left bank and the crank were spot on and the engine rolled over by hand just fine. Runs perfect.

Yes, I know that timing belt is bad.

It doesn't take long at all to pull the right bank timing cover. Set the crank to zero degrees, pull the right bank cover and make sure it's on the mark. If not, rotate the engine over until the crank and right bank line up. Then pull the upper 10mm bolt on the left side timing cover and take a flat head screwdriver and gently pry back, shine a flashlight inside and see if it's on it's mark. I don't know if just pulling the one bolt and prying the cover will work but it's worth a shot compared to having to remove that sides cover. It's kind of a PITA.

So, take the 30 minutes and check it yourself and go from there. How much power and fuel do you think youre missing?

 

[AMGAndrew]

Mack also brings up a good point with the fueling. When pulling the battery, the ecu looses all it's "learned" calibrations and it will take a few days to gain it all back. Totally forgot until now but I also cleaned the throttle body when I did the TB/WP and my idle was something like 1200 in neutral and 1000 in drive. After a few days, the ecu recalibrated and all was back to normal.

 

[C6H12O6]

I noticed mine was getting crappy gas mileage after the timing belt replacement, but it runs great. I attribute my MPG drop to a simultaneous drop in my right foot. Downright sporty with new plugs, fresh oil, and a clean intake.